The present invention is directed to a compensating element for a fuel injector.
German Published Application No. 197 35 665 describes a fuel injection system that has a compensating element made of a supporting body having a dome-shaped supporting surface. This compensating element supports a fuel injector in a receiving bore of a cylinder head. Since the fuel injector rests on the spherically shaped calotte surface by way of a supporting surface, the fuel injector can be mounted at an angle that deviates from the axis of the receiving bore by up to a certain amount, and can be pressed firmly into the receiving bore using appropriate means, e.g., a clamping shoe. This allows a simple adaptation to be made to the fuel supply lines. Tolerances arising in the manufacture and in the mounting of the fuel injectors can be compensated for.
It is disadvantageous, however, that the supporting body requires expensive manufacturing and that a precisely manufactured, spherical surface is needed. The rigid supporting body cannot be compressed, and thus no compensation in the axial direction of the receiving bore takes place. Moreover, tolerance can only be compensated with respect to the specified geometry of the spherical surface. A radial compensation movement purely with respect to the receiving bore is not possible.
In contrast, the compensating element according to the present invention for a fuel injector has the advantage over the fuel injector and are in turn connected to sphere-segment-shaped supporting segments which wrap around the fuel injector and thus provide spacing from a wall of a receiving bore of a cylinder head of an internal combustion engine in accordance with the forces exerted on the fuel injector.
The compensating element compensates both for manufacturing tolerances of the individual components as well as for tolerances that are caused by the warming of the fuel injector during operation, and in this manner prevents twisting and misalignments.
It is particularly advantageous that the intermediate ring has a quadrantal-shaped cross section and is positioned between the fuel injector and the wall of the receiving bore in such a way that the fuel injector is able to be flexibly balanced in the receiving bore.
Furthermore, it is advantageous that the intermediate ring is easy to produce from plastic. The webs may be integrally formed with the intermediate ring or be extruded onto it. The totality of the supporting segments advantageously form a circle which completely surrounds the fuel injector. The number of supporting segments preferably amounts to four, these being supported by two or four webs.
The webs may be elongated and have a retaining collar, which allows the compensating element to be affixed to the fuel injector.